Elevator control



March 23, 193

Filed Dec. 21, 1934 E. L. DUNN ET AL.

ELEVATOR CONTROL l3 Sheets-Sh eet l HOISTING SHEAVE QONTROL HOISTINBMOTOR- RELAY PANEL HE PANEL SELECTOR MMHINE OVERHEAD sHEm/Es TAPE DRIVEJam HALL LANTE -5E I COUNTERWEIGHT HALL BUTTON-EI HALL LANTERNS-QE HALLhumus-g m I d ill a I CA OF AND m 25 9 POSHBIOSNTINDIGATOR SW|TCH ZMANUAL DIRECTION 2 BUTTONS *w .fiH IONTROL SWlTCH Z; eggRa iucY 95' 634T S ITCH HALL LANTERN%E CAR STARTNG. 1652 swncn H m HALL BUTTON?)ELEVATOR (AR 555 H W L4,, 41%

llNVENTORS ELEVATOR CONTROL Filed Dec. 21, 1954 13 Sheets-Sheet 2 FIGZ41% M M NVENTORS ATTORNEY MMQE'A 9 1937 E L. DUNN ET AL ELEVATOR CONTROLFiled Dec. 21. 19341 13 Sheets-Sheet i m m 9Q 0 0 m; 2

}INVENTOR5 ATTORNEY QM AK 4W, 4W 0M1 LAM BY um.

Mamh 23;, 19370 E L U ET AL fl i wfi ELEVATOR CONTROL Filed Dec. 21,1934 13 Sheets-Sheet 4 }INVENTORS V'ATTORNEY March 23,1937. E. DUNN ETAL ELEVATOR CONTROL Filed Dec. 21, 1934 13 Sheets-Sheet 5 moi ATTORNEYMarch 23, 1937. E. L. DUNN ET AL 2,071,578

. 'ELEVATOR CONTROL Filed Dec. 21, 1934 '13 SheetsSheet e i 855 V 7% 335w 79! a 3' 554 all g 3 804 805 55 5 i g :11 703 \i 822 s05 a;

8.2 FIGIS [4 46M QWL hNVENTORS March 23, 1937. E. L. DUNN ET AL2,074,578

ELEVATOR CONTROL Filed Dec. '21, 1934 13 Sheets-Sheet '7 @@@@@Ofi)-L@@@@@GE}L 43W ma KM |NVENTOR5 raw W ATTORNEY March 23, 1937. D NN ET AL2,074,578

ELEVATOR CONTROL Filed Dec. 21, 1934 13 Sheets-Shegt 8 1C a g INVENTORSBY ATTORNEY March 23, ,1937. E. L DUNN ET AL 2,074,578

ELEVATOR CONTROL Filed Dec. 21 1934 13 Sheets-Sheet 9 8-1 4 I an as 9121 5, 9

= lazo 902 FIGZZ CM A INVENTORS BY ATTORNEY March 23, 1937.. E. L. DUNNET AL 2,074,578

ELEVATOR CONTROL Filed Dec. 21, 1934 13 Sheets-Sheet 10 H fi ljlNVENTORS.

ay. I? I m ATTORNEY March 23, 1937. E. L. DUNN ET AL 2,074,578

ELEVATOR CONTROL Filed Dec. 21, 1934 13 Sheets-Sheet l1 ,eelso m new 240"0 FUN) }INVENTOR5 ATTORNEY E. DUNN ET AL 2,074,578

ELEVATOR CONTROL March 23, 1937.

Filed Dec. 13 Sheets-Sheet 12 F IG.Z b

4 M }INVENTORS BY ATTORNEY Patented Mar. 23," 1937 UNETEE STATES T QFFEEFATE ELEVATOR CONTROL ration of New liersey Application December 21,1934, Serial No. 758,548

55 @laims.

The invention relates to elevators. It is directed to the cor. :rol ofcertain operations of the elevator car and to mechanism employed in,efiecting such control.

Although certain features of the invention are of utility in connectionwith simple forms of elevator control, the invention is of particularutility in connection with elevator controls which are in comparisonexceedingly complicated. In order that all the features and advantagesof the invention may be readily understood, it will be described asembodied in one of these more complicated forms of control. In view ofthe complexity of such system, its operation will-first be outlined asan aid to an understanding of the principles and features of theinvention.

The starting of the elevator car after each stop is under the controlof'an attendant inthe car...

while the stopping of the car is automatic. Stops to dischargepassengers are made in response to push buttons within the elevator caroperated by the attendant as directed by the passengers.

Steps to take on passengers are made in response to push buttons at thelandings operated by the intending passengers themselves. Such controlas applied to a plurality of elevator cars involves controlling thestopping of all cars by the push buttons at the landings, these buttonsbeing common to the cars.

The starting of the car is efiected by a manual operation on the part ofthe car attendant. Mechanism actuated in accordance with movement of theelevator car is provided which cooperates with stationary circuitcontrolling means to select the floors at which stops are to be made tobe in accordance with the push buttons operated. When the car nears thelanding for which a push button has been pressed it is caused to slowdown. It is thereafter brought, to a stop as to it arrives at thelanding. A light is lighted at the floor in accordance with thedirection in which the car is to leave the floor for the information ofintending passengers. Stops are made in the natural order of floors,regardless of the order in which the push buttons are operated. When aplurality of elevators are operated in a group, but one car is caused torespond to each operated hall button, the car selected being determinedby the relative positions of the cars and their directions of travel.

One feature of the invention resides in the provision of a. plurality ofswitches for controlling the speed of an elevator car whichare actuatedby car movement to control the complete slow down of the car for eachfloor, regardless of the slow down distance involved.

Another feature of the invention is to operate the speed controllingswitches in effecting the starting of the car and to cause the number ofswitches operated to be in accordance with the slow down distanceinvolved in the next stop to be made.

Another feature is to advance a device, carried by a member actuable inaccordance with car movement, with respect to this member as the speedcontrolling switches are operated in efiecting the starting of the carand to bring the device to a stop by stopping means provided for thefloor at which the next stop is to be made, either in a partially orfully advanced condition depending upon the length of the run to thatfloor, the number of speed controlling switches operated beingdetermined by the amount of such advance.

Still another feature of the invention is to take up the advance of thedevice after it has been brought to a stop by movement of said member inaccordance with car movement and in so doing to restore the speedcontrolling switches as the car arrives at decreasing distances from thefloor;

Another feature is to effect the advance of said device prior to theactual starting of the car.

Another feature resides in the provision of mechanism for facilitatingthe setting of the speed control switches. j

Another feature of the invention is to arrange the mechanism, whichcooperates with the stationary circuit controlling means, on said deviceto be advanced thereby with respect to said memberactuated in accordancewith car movement.

Another feature is to stop the movement of said device upon cooperationof said mechanism with stationary circuit controlling meanscorresponding to an operated push button.

Still another feature is to effect cooperation between the mechanismcarried by said device and each stationary circuit controlling means forbut a fraction of the time that they are opposite each other.

Another feature of the invention is to cause the period during which ahall light is lighted to be of maximum duration without false orduplicate indications.

.Another feature of the invention resides in improvements in mechanismfor bringing the car to an exact landing level. I

There are many other features and advantages. These will be set forth inthe following description and appended claims. v

In the drawings: I

Figure 1 is a simplified schematic representation of an elevatorinstallation in accordance with the invention;

Figure 2 is a schematic representation of the selector machine used inthe control system;

Figure 3 is a detail in side elevation of the selector switches andoperating mechanism therefor;

Figure 4 is another detail of the same in front elevation, Figure 3being taken along the line 3--3 of Figure 4; I

Figure 5 is a fragmental detail of one of the selector switches and, itsoperating cams as viewed from above, this view being taken along theline 5-5 of Figure 3;

Figure 6 illustrates the settings of the operating cams for the selectorswitches, these views being taken along the lines A-A, B-B, C.C,

0 D-D, E-E and F-F of Figure 4;

Figure '7 is a detail in side elevation illustrating the advancermechanism for the brushes and pawls on the selector machine carriage,the counterbalance therefor, and the scale for setting the selectorswitches;

' Figure 8 is a detail of the same in front elevation;

Figure 9 is a detail in side elevation of mechanism for retracting thepawls and a control switch operated thereby for the advancer mechanism;

Figure 10 is a detail of the same in front elevation;

Figure 11 is a top view of a floor bar of the selector, illustrating thearrangement ofthe stationary contacts and floor brush switch thereon,and also illustrating thetravelling brushes for engaging the stationarycontacts and the cam for operating the floor brush switch;

Figure 12 is a detail in front elevation of the stopping, reset, halllight, and automatic reversal brushes, and the operating cam shown inFigure 11;

Figure 13 is a side view of the frame which.

carries the stopping brushes, illustrating the arrangement forcontrolling the manner in which the stopping brushes engage theircooperating stationary contacts;

Figure 14 is a side view taken along the line Ill-i4 of Figure 12,showing one of the stopping 1 brushes and also showing the manner inwhich it cooperates with a stationary contact;

Figure 15 is a side view taken along the line l5l5 of Figure 12, showinga reset brush in engagement with a stationary contact;

Figure 16 is a detail in front elevation of the remaining brushes shownin Figure 11; K Figure 1'7 is a view in side elevation taken along theline 11-11 of Figure 16, showing the details of the brush forcontrolling the point at which automatic door opening takes place andalso showing the.manner in which this brush cooperates with a stationarycontact;

Figure 18 is a top view, with parts broken 5 away, showing the detailsof a floor brush switch;

Figure 19 is a view in front elevation showing the arrangement of thefloor bars for several floors;

Figure 20'is a schematic representation of the 7 levelling mechanism;

Figure 21 is a detail in side elevation of a switch unit of thelevellingmechanism;

Figure 22 is a top view of the same;

Figure 23 is a diagrammatic representation of 7 the control panelshowing the relationship of v ropes for the car and counterweight.

the coils and contacts of the various switches mounted thereon; andFigures 2411, b and-c, taken together, constitute a simplified diagramof the power and control circuits for one elevator.

For a general understanding of the invention, reference may be had toFigure 1, wherein various parts of the system, chosen to illustrate theprinciples of the invention, are indicated by legend. The elevator caris raised and lowered by means of a hoisting motor. This motor drives atraction sheave over which pass the hoisting An electromagnetic brake isprovided and is applied to effect the final stopping operation and tohold the car when at rest.

A plurality of control switches are provided in the car, some of whichare shown in Figure 1.

These switches include a motor generator starting switch, a non-stopswitch, a series of push button switches, an emergency stop switch, adirection control switch and a car starting switch. All of theseswitches are for operation by the car attendant.

The car starting switch comprises a plurality of pairs of contactsdesignated H2, 58!, 59 1 and GI. Bridging contacts 630, GM and 632 aremounted on a pivoted segment 333 for bridging these pairs of stationarycontacts. Segment 633 is operated by means of operating handle 634. Thecar starting switch segment may be moved into three different operativepositions from neutral. Two of these operative positions are attained'by movement of the segment counterclockwise about its pivot. In one ofthese positions, contact 6 3l bridges contacts 58!. Furthercounterclockwise movement causes contact 630 tov bridge. contacts H2 andcontact 632 to bridge contacts 591. Contact 63I is elongated so as tomaintain contacts 581 bridged in this second position of the car switch.This second position .is the full start position of the switch, to whichit must be moved to effect the starting of the car.

The car starting switch also controls the closing and opening of the cargate and hatchway doors. The door and gate closing operation is efiectedby moving the car starting switch to its first or intermediate position,where contact 63! bridges contacts 58L The bridging of contacts Billalso causes certain other control operations to take place, which willbe discussed later. The preferred operation, however, is to move thestarting switch immediately from neutral to full start position. Theopening of the car gate and hatchway door is effected by operatinghandle 634 to move segment 633 clockwise about its pivot into positionwhere contact 632 bridges contact 6|. The car cannot start unless thecar gate and all the hatchway doors for that car are closed. The slowingdown of the car preparatory to stopping to effect passenger transfers isinitiated in response to the push buttons within the car and also topush buttons at the landings. The pressing of a car button causes thecar, upon its arrival at the proper slow down distance from the floorcorresponding to the button pressed, to be slowed down and thereafterbrought to astop with the car level with the landing. There is only onecar button in the car for each floor, these buttons serving both as upand as down travel, the same button is effective to cause 'slow down tobe initiated upon the arrival of the car at a certain distance above thelanding. The car buttons, once pressed, are held in operated conditionby means of a magnet I93. This so that subsequently operated car buttonsare again held in operated condition.

Where a plurality of cars are operated as a group, the push buttons atthe landings are common to all the cars of the group and are capable of.causing the slowing down of any one of them.

Both an up hall button and a down hall button are provided at eachintermediate floor served by "the cars of the group. When an up hallbutton is pressed, the first available up travelling car is caused toslow down and thereafter to be brought to a stop at the floor at whichthe button is located. Similarly, when a down hall button is pressed,the first available down travelling car is caused to slow down andthereafter to be brought to a stop at the floor at which the button islocated. A hall button may be provided also at each of the terminalfloors.

The hall buttons act through floor relays arranged on the relay panel.Each relay, once operated, is maintained so, permitting the push buttonwhich causes the operation to be released. The floor relays illustratedin the control system are of the latching type. Such a relay comprisesan operating coil for causing the operation of the relay, latchingmechanism for latching the relay in latched condition and a reset coilenergizable to releasethe latching mechanism. The reset coil of anoperated floor relay is not energized and therefore the relay isretained in operated condition until circuits are set up to answer thecall registered thereby. The reset of the'relay avoids causing othercars to be slowed down in answer to that call.

The floors are served in the natural order of floors for each directionof car travel, regardless of the order in which the push buttons for thefloors are operated.

The slowing down of the car, preparatory to bringing it to a stop at afloor for which a push button has been pressed, is initiated by aselector machine for that car The selector machines for the cars of thegroup also select the car which answers each operated hall button. Theseselector machines, in cooperation with other control apparatus, actautomatically to select the first available car to respond to anoperated hall button. This car may not-be the car nearest the floor atwhich the button is located, but it is the car which is in efiect thenearest car. 'The selector machine of the car to be stopped also causesfurther slow down to take place and finally causes the car to be broughtto a stop at the floor landing.

Each selector machine is driven preferably by means of two steel tapesattached to the car. One tape extends from the top of the car to anoverhead sheave. The other tape extends from the bottom of the cararound a tension sheave and then up to a second overhead sheave. Thetapes are wound on the overhead sheaves in a manner similar to thewinding of a measuring tape, one being wound oppositely with respect tothe other. The shaft upon which the overhead sheaves are mounted drivesthe selector machine through a chain and sprocket. One tape is un= woundas the other is wound up in effecting the driving operation.

Each selector machine comprises a crosshead which is driven by a screw,which is in turn driven by the chain and sprocket, to move in accordancewith movement of the car for which the machine is provided. Thecrosshead carries a carriage upon which is mounted mechanism for settingup circuits to cause the car to be slowed down and stopped at a floor.Mechanism is also mounted on the carriage for causing slow down to beginwhen the car arrives at a certain distance from the floor and forcausing further slow down as the car arrives at decreasing distancesfrom the floor. The carriage is advanced from a neutral position withrespect to the crosshead in starting the car and its advance. is stopp dafter a certain amount of movement by its engaging a stop. Thereafterthe carriage moves with :the crosshead. When circuits are set up tocause the car to be slowed down, the carriage is brought to a stop. Thismay occur before the carriage is fully advanced on a short run. Inanycase, the crosshead, which moves with the car, thereafter takes upthe advance of the carriage so that when the car comes to a stop, thecarriage is again in neutral. This relative action of the carriage andcrosshead is utilized to control the slow down of the car.

Signals are arranged at the floors for advising intending passengers ofthe approach to the floor of a car which is to be stopped thereattoeffect a transfer of passengers. These signals are preferably in theform of lamps, usually known' as hall lanterns.

Each car is provided with both an up hall lantern and a down halllantern at each intermediate floor, an up hall lantern at the lowerterminal and a down hall lantern at the upper terminal. The up halllanterns at intermediate floors are lighted during upward travel oftheir respective cars and the down hall lanterns at intermediate floorsare lighted during downward travel of their respective cars. Whencircuits are set up incident to answering the highest call to cause thedirection of an up travelling car to be reversed as the car comes to astop, the down hall lantern for that car at the floor at which the stopis being made is lighted instead of the up hall lantern at that floor.

A maximum duration of lighting of the hall lantern is provided. The halllantern is lighted as soon as circuits are set up by the selectormachine to cause the car to be slowed down and stopped at a. floor. upbefore the carriage becomes fully advanced, the hall lantern for thatcar for the floor for which the circuits have been set up is lightedbefore the car starts. When full advance of the carriage has beenobtained and the car has started, the proper hall lantern is lightedimmediately circuits are set up to cause slow down and stopping of thecar to take place. The hall lantern is maintained lighted during theslow down and stopping period and while the car is stopped at a floor.It is not extinguished until the car starting switch has been moved tostart position to start the car. The circuits for the hall lanterns arecontrolled by the selector machines.

'Mechanism is also provided for each car for causing the car, upon beingbrought to a stop, to come to an exact landing level in case of anoverrun or an underrun. This levelling mechanism may be arranged on theselector machine.

The electromagnetic switches for controlling In case'such circuits areset I the operation of each elevator are mounted on the control panelfor that elevator.

Many of the mechanisms and elements which go to make a completeelevator-system have not been illustrated in the drawings. Among theseare the safety devices, including the safety governor, safety brake,bufi'ers, limit switches, and various auidliary switches included in theelevator car for operation by the car attendant. The system will bedescribed in connection with the wiring diagrams as. applied to aten-floor installation. It is to be understood, however, that the systemmay be arranged for an installation of any number of floors.

Reference may now be had to Figure 2, which illustrates schematically aselector machine of preferred construction. This figure is princi-'pally used to give a more comprehensive understanding of the machine andits operation. It is not intended to show the details of construction,the details of the various parts of the selector machine beingillustrated in Figures 3 to 22 inclusive. In the drawings showingdetails of construction, certain parts, not involved in the operation ofthe portion of the mechanism illustrated in a particular figure ofdrawings, are not shown in that figure in order that the constructionand operation of such portion of the mechanism may be readilyunderstood.

Referring first to Figure 2, the selector machine comprises a frameformed by a base plate 656, four standards 65!, and a top plate 652supported by these standards. The standards are secured in socketsformed in bosses both on the base plate and the top plate. Thebase plate650 is formed with a centrally disposed pedestal 653, which, togetherwith a boss formed on the base plate at one side thereof, providesbearings for the selector machine operating shaft 654. The

. screw is supported at its lower end by a ball thrust bearing and atits upper end extends into a bearing in a boss depending from top plate652.

The vertical screw 656 drives a crosshead 660. This crcsshead comprisesa split nut SH and guides 662 and 663 connected to the nut by flangesand cooperating with vertically extending guide bars 664 and 665respectivelyto prevent rotative movement of the crcsshead and to guideit as it is driven upwardly and downwardly by rotative movement of screw656. The guide bars 664 and 665 extend from the base plate to the topplate and are secured to bosses formed on these plates.

The crosshead carries a plurality of switches I62, 51, I2l, Isl, I54 andI62. These switches are principally for controlling the retardation andstopping of. the car. They also serve to determine the amount ofacceleration on short runs. These switches are arranged within a boxlike frame 666. The frame is formed with lugs 661 (Figure 8) providedwith aperatures through which screws 668 (Figure 2) extend into threadedbosses on the guide portions 662 and 663 of the cr osshead, securing theframe to the crcsshead. Each of the switches is of the sameconstruction, the construction of one of them being shown in Figures 3and 5.

Referring to these figures, a switch panel 610 is mounted on a bracket6" secured to the frame 666. A bearing bracket 612 issecured to the faceof the panel. This bracket comprises a pair of apertured lugs 613connected by an elongated web 614. An elongated pivot pin 615 extendsbetween the lugs 619 and is supported in the apertures. This pin issecured in place as by screws 616. The contact levers 611 of theswitches are mounted in side by side relation on pin 615 between thelugs. These contact levers 'carry spring contacts 618 for cooperatingwith stationary contacts 619 secured to the switch panel.

Each of. these switches is of the same construction. The stationarycontact of each switch comprises a contact stud provided with a tungstencontacting tip 666 on its contacting end. The other end of the stud,which extends through the panel, is threaded and is provided withbinding nuts for securing the stud to the panel and connecting thecontact in the system. The movable contact for engaging the stationarycontact is likewise tungsten tipped, this tip being carried by the endof the contacting spring 618. The contacting spring is of leaf springconstruction, preferably of a. bronze alloy. It extends downwardly intoa channel formed on the contact lever by lugs 682, at which point it issecured to the lever as by a screw. This screw also secures a clip fromwhich a flexible conductor 683 extends to a binding post 684.- At theupper end of the contact lever, the spring extends through a slot whichserves to protect the spring from being bent out of shape. 6

The contact lever is of insulating material and is pivoted on pin 615 ata point below the lugs 682. The contact lever is biased into positionwhere the movable contact is disengaged from the stationary contact asby a spring 686 extending from a locating slot in the panel to thecontact lever at a point between the lugs 682 where the securing screwfor the movable contact serves as a spring seat. Below its pivot pointthe contact lever is formed with a depending stop arm 681 arranged tocooperate with web 614 to form a stop to limit the amount of movement ofthe contact lever by its biasing spring 666. Above its pivot point thecontact lever is formed with outwardly extending lugs 696 provided withapertures through which extends a pivot pin for an operating roller 69!.This roller is positioned in the path of movement of cams 692 and 698 tomove the contact lever about its pivot against the force of spring 666into contact engaging position.

The operating cams for the switches are secured to an operating shaft694 rotatively supported in bosses 695 formed on the frame 666. Thesecams are arranged side by side on shaft 694. Each cam is arc-shaped, thecamming surface being the arc of a circle with the centercoincidingiwith the center of. the operating shaft. The cam is clampedto the shaft-by means of a clamping plate 691 secured aszby screws to acounterpart 696 formed integral with the cam. The cams are positioned onthe shaft so that the two cams for operating each switch straddle theoperating roller GM for that switch.

With the car stopped at a floor the cams as sume a position in whichtheir'leading edges are substantially equally spaced from the rollerswhich they operate,- so that substantially the same amount of rotativemovement is required in one direction as in the other to close eachswitch. The cams are set so that their leading edges are increasinglyfarther from the rollers of'theswitches'which they operate, in the orderof switches I02, 51, I21, l3l, I54 and I62. In other words, uponrotative movement of the operating shaft in either direction, theswitches are closed in the order of switches I02, 51, I2I, I3'I, I54 andI62. The relative positions of the cams of the various switches withrespect to the rollers l with the cam shaft in neutral are shown inFigure 6, wherein the switches operated by the cams are indicated inparentheses above the respective pairs of cams.

The rotative movement of the cams to close 10 the switches is effectedby a split field torque motor 698 through a train of gears I00. Themotor and gears are mounted on the frame 666, the motor being positionedover the cams as illustrated in Figure 4. l5 Reverse rotative movementof shaft 694 to return the cams to positions permitting the opening ofthe switches by springs 686 is effected by movement of the'elevator carin moving crosshead 660. Referring back to Figure 2, in rotating shaft694 to effect the closing .of the switches, the motor also acts througha gear IM and rack 102 meshing therewith to vertically move a carriage103, either up or down, depending upon the direction of rotation of theshaft. This advances 35 the position of stopping pawls I04 and I withrespect to the crosshead 650. These pawls co- .operate with stoppinglugs I06, one for each floor, secured to one of the standards 65I, tobring carriage I03 to a stop. Thus, the rack I02 is stopped so that asthe car continues to drive crosshead 660, gear TM is rotated by the rackin a direction to move operating cams for the selector switches back tothe positions illustrated in Figure 6. Actually, the cams for eachswitch will not be equidistant from the operating roller for that switchwhen the car is stopped at a floor, one or the other cam, depending uponthe direction of car travel, being closer to the roller due to certainworking clearances allowed for the pawls.

40 Details of this portion of the mechanism are shown in Figures 7 and8. The toothed rack I02 which meshes with gear I0! is secured to thecarriage I03 as by screws 699. The carriage is guided in its upward anddownward movement 45 by means of guide bars I01 and I08. These barsextend into sockets provided in bosses formed on brackets H0 and II I.These brackets are secured to frame 666 by means of screws extendinginto threaded bosses provided on extensions H2 and 51 H3 of'the frame.The carriage is formed with a horizontal extension H4 which, as will beshown later, provides a support for the crosshead panel for thetravelling brushes. Extension H4 is formed with bosses provided withapertures 55 through which the guide bars 101 and I08 extend,

thereby forming guides for the carriage.

Upon clockwise rotative movement of gear IOI as viewed in Figure '7, therack I02 and carriage 103 are moved downwardly on the guide bars. mThismovement continues so long as operating shaft 694 is rotated bymotor 698 until the car-' riage engages stop collar H5 provided on guidebar I08. A similar stop collar II 6 is provided on guide bar 108 abovethe carriage to limit the amount of upward movement on the bars uponcounterclockwise rotative movement of gear'10l by the motor. Thismovement of the carriage on its guide bars is relative to frame 666 andtherefore to the crosshead 660. The motor is controlled to effect thismovement of the carriage in the same direction as the crosshead is to bemoved. Thus the relative movement between the carriage and the crossheadis one of advancement. In

u motor with respect to the crosshead.

The pawls I04 and I05 carried by the carriage I03 are pinned to shaftsIII and H8 rotatably supported by the carriage. These shafts extend.through apertures provided in flanges I20 on the carriage and aperturesprovided in bosses I2I also formed on the carriage. Compression springsI22 are arranged between spring seats formed on the pawls and on thecarriage to bias the pawls outwardly from the carriage. The pawls arereversed so that pawl I04 is biased by its spring for clockwise rotativemovement about shaft III while pawl I05 is biased by its spring forcounterclockwise rotative movement about shaft I I 8. An arm I23 issecured to each operating shaft Ill and H8 on the other side of boss I2I. These arms rotatably support rollers I24. The pawls are retractedagainst the force of springs. I22 to clear the stopping lugs by pushingthe rollers I24 outwardly from the carriage .103.

Referring back to Figure 2, the rollers are moved outwardly to retractthe pawls by means of a. cam I30. The cam is carriedby the crossheadthrough the interme-iary of hell crank levers I3I and I32. Anelectromagnet I33 carried by the crosshead is provided for controllingthe action of cam I30. This magnet comprises two coils 5II and 543. Thecontrol system is arranged so that the coil 5'" is energized to effectthe retraction of the pawls whereas, to permit the pawls to bereextended for cooperating with the stopping lugs, coil 548 is alsoenergized to magnetically neutralize coil 5'. Upon the energization ofcoil 5'II, thebell crank lever I3I is' pulled upwardly and, through linkI34, bell crank lever I32 is also pulled upwardly, causing the cam to beextended outwardly to push rollers I24 away from the carriage.

This rotates the shafts Ill and H8 in a direction 7 to force the pawlsinto retracted positions against the force of springs I22.

In moving outwardly, cam I30 acts through link I35 to pull contact leverW36 clockwise about its pivot to close'contacts of a switch whichcontrols the energization of motor 698. Thus the motor for advancing thecarriage is not energized until the pa'wls are moved to retractedposition.

The details of the mechanism for operating cam I30 are shown in Figures9 and 10. The'upper bell crank I 3| for operating the cam is pivotallysupported by a channel-shaped extension I40 formed on bracket H0. .It ismounted on a pivot pin I43 supported by extension I40 and extendingthrough apertures formed therein. One arm I4I of the bell crank isconnected to cam 130 by a pivot pin I42. The other arm I44 of the bellcrank extends substantially horizontally, being formed with two lugs"I45 at its pivotpoint to straddle extension I40. At its outer end, armI44 adjustably supports a movable core I46 for magnet I33.- The magnetis supported by bracket I I 0, its stationary core being secured in anaperture formed in the bracket. The magnet coils 511 and 548 are held inposition on the stationary core by means of the clip I50 securedto'extension I40 by a screw.

The link I34 is connected to bell crank I3I by means of a pivot pin 'I5Iextending through apertures in the link and a lug formed on arm I44. Thelink is similarly connected to arm I52 of hell crank I32. This bellcrank is pivotally supported by an extension I53 formed on bracket II I.The upwardly extending arm I54 of the bell crank is connected to cam I30by pivot pin I55. The com is formed with outwardly extending or steppedportions I56 and I51 at its upper and lower ends respectively. Thepurpose of this construction will be explained later. Cam I30 is biasedto its retracted position by arms laid and I52 of the bell cranks,linkage i8 5 and movable core 766. A lug I55 is formed on arm 152 forcooperating with adjustable stop 359 to bring the cam to a stop in itsretracted position. The mechanism is illustrated with cam 33b inextended position in Figures 9 and 10.

The switch operated by the cam is mounted on the panel I60 secured byscrews extending into threaded apertures in bosses ltl formed onextension N3 of frame 686. The switch comprises three pairs of contacts5%, 583 and 586. Each pair of contacts is of the same construction. Thestationary contact comprises a contact stud ltd secured to the panel andhaving a tungsten-tipped contact point 155. The movable contact IE6 forengaging the stationary contact is likewise tungsten-tipped. Thismovable contact is in the form of a.leaf spring, preferably of a bronzealloy, which extends downwardly into a channel it? formed on the contactlever TIES, atiwhich point it is secured to the lever as by a screw.

All three of the leaf springs are secured to the one contact lever 18%,the channels it? being arranged side by side. Slots are provided in thecontact'lever at the upper end through which the leaf springs extend.These slots serve to protect the springs from being bent out of shape.Connections are taken from the contacts at the contact studs and at thebinding nuts for the securing screws for the leaf springs.

The contact lever is of insulating material and is pivotally mounted onshaftfltd supported by bearing brackets Tifi secured to the panel. Atits lower end the contact lever is formed with an arm ill to which thelink I35 which connects the lever to cam I30 is 'pivotally secured.

The weight of the carriage 703 and mechanism carried thereby, includingthe panel I9I and parts mounted thereon, to be described later, iscounterbalanced. Referring to Figures '7 and 8, the coun- 1 terbalancingmechanism comprises a counterweight I75 connected by a sprocket chainI16 to a sprocket 'III mounted on operating shaft 69d to be rotatedthereby. The chain is secured to the sprocket by a pin passing throughthe end link of the chain. After extending substantially half way aroundthe sprocket, the chain passes upwardly over a pulley TF8 pivotallymounted on a pin 780 supported by guide bars 'I8i for the counterweight.These guide bars are secured to frame 665 as by screws, and extend intoslots I82 provided in the counterweight to guide the counterweight inits upward and downward movement. Spacing bars I83 are provided betweenthe guide bars and frame 666 to extend the counterweight outwardly asufiicient distance to clear the frame. With this arrangement, uponrotative movement of the torque motor 698 in a direction to advance thecarriage in the upward direction, the chain is unwound from thesprocket, lowering the counterweight. When the. torgue motor is rotatedin the opposite direction to advance the carriage downwardly, the chainis wound onto the sprocket, lifting the counterweight. Thus thecounterweight efiectively counterbalances the weight of the. carriageand parts carried thereby.

Referring back to Figure 2, the operation of the mechanism so fardescribed is as follows: Upon energization of coil 5'", bell cranks 1-3!and I32 are pulled counterclockwise about their pivots. This extends camI30, which pushes rollers I24 outwardly, swinging pawls I04 and I05about their pivots against the force oi their biasing springs toretracted positions. Cam E30, in moving outwardly, acts through link I35to swing contact lever I35 to contact engaging position. This causes thecircuit for motor 698 to be completed. The motor acts through gearing Ito rotate operating shaft 594. The direction of rotation is determinedby the control system, which will be described later.

.Assume that the controlling mechanism is set for up travel of theelevator car. Under such conditions, the torque motor rotates shaft 694in acountercloekwise direction as viewed in Figure 7. Thus, the leadingedges of the cams 692 engage the operating rollers of selector switchesB2, 57, I2I, ISI, I56 and I62 in the order named, to move these switchesto closed positions.- At

the same time, gear ml moves rack I02 in the up direction, causingupward movement of the carriage I03. When the carriage engages stopcollar H6 on guide bar I08, it is brought to a stop. This preventsfurther rotative movement of gear ml, which brings operating motor 698to a stop.

When circuits are set up to cause the car to be slowed down and broughtto a stop at a hour, coil 508 of magnet I33 is energized, neutralizingthe magnetic action of coil 517. This releases bell cranks ISI and I32and cam I30 is returned to retracted position. This return movement iseffected quickly due to the kick ofi action of pawl springs I22. PawlI05 is thus extended for cooperation with the stopping lug I06 for thefloor for which the circuits have been set up. The mechanism whichcauses the setting up of these circuits acts to efiect theneutralization of coil 5'" and the retraction of cam I30 at a pointwhere pawl I05, upon being extended by its biasing spring, isimmediately beneath the stopping lug.

Only pawl T05 is effective for cooperation with the stopping lugs duringup car travel. Pawl I04 is effective only during down car travel. Thus,pawl I05 may be termed the up stopping pawl while pawl I0 5 may betermed the down stopping pawl. The return of cam I30 to retractedposition also causes movement of contact lever I36 about its pivot toopen the contacts. This causes the motor 698 to be deenergized.

The small clearance between up pawl T05 and the stopping lugis taken upby the upward movement of crosshead 660 as a result of upward movementof the elevator car. The engagement of pawl I05 with the stopping lugbrings the carriage I03 to a stop. The crosshead, however. continues tobe driven upwardly by the elevator car, taking up the advance of thecarriage. As

continued upward movement of the crosshead a stop at the floor level,the car being stopped as a-result of the opening of switch I02 justbefore thecar reaches an exact level with the landing.

, Had the controlling mechanism for the elevator car been set for downtravel instead of up travel, the torque motor would have beenenergizedby the closing of switch contacts controlled by magnet I33 so as torotate shaft 694 in a clockwise direction as viewed in Figure 7. Undersuch conditions, the selector switches are closed by cams 693 instead ofcams692. Gear IOI moves rack I02 in the down direction, causing downwardmovement of carries I03 until it is brought to a. stop by engaging stopcollar on bar I06. When 5 circuits are set up to cause the car to beslowed down and brought to a stop at a floor during downward travel,coil 548 is again energized to neutralize the magnetic action of coil5". Cam I30 is thereupon retracted and down stopping pawl 104 isextended for cooperation with the stopping lug I06 for the floor forhave been set up. When the engagement of pawl I04 and the stopping lugoccurs, the carriage is brought to a stop but the crosshead continues to5 be driven downwardly by the elevator car, taking Thus, gear ml 0 turnof cams 693 to the position shown in Figure 6 and the opening ofselector-switches I62, I54, I3I, I2I, 57 and I02 in sequence in theordernamed.

This causes the car to be slowed down and brought to a stop at the floorlevel.

In the preferred arrangement of control which will be discussed later,the energization of coil 51! is effected to cause the energization oftorque motor 698 and this torque motor operates to complete theadvancement of carriage 103 before the starting of the car takes place.The carriage may be moved to full advanced position or it may be broughtto a stop before reaching this point. 'If circuits are not set up tocausethe car to be brought to a stop at a floor before the carriagereaches full advanced position, the carriage is brought to a stop uponengagement with one of the stop collars I I 5 or II 6 and motor 698remains energized until such circuits are made. However, should suchcircuits be set up before the carriage 40 becomes fully advanced, thetorque motor is deenergized-and the carriage comes to a stop. Thesetting up of circuits to cause slow down and stop occurs when astopping brush on the selector engages an alive contact, as will beshown later.

When circuits are set up to cause slow down and stop with only a partialadvance of the carriage, the clearance between the pawl and stopping lugis taken up by the starting of the car to move the crosshead an amountsuflicient to effect this engagement. When full advance of the carriagehas been attained, however, the car will be in motion at the time thecircuits are set up and the car continues to drive the crosshead afterthe pawls are released. taking up the clearance. In either case,continued movement of the crosshead takes up the advance of the carriageand in so doing causes the return of the cams of shaft 594 to switchopening positions from the positions to which they have moved,openingall of the selector switches which were closed.

Selector machines of a construction shown on these drawings alreadybuilt have been geared at a ratio of 120 to l, i. e., the crossheadmoves 1 foot for each 120 feet of car travel. A scale I is secured torack I02 and is marked off in feet at this ratio. The scale is graduatedthe same on each side of the neutral point, the ungraduated space in themiddle being for the working clearance of the pawls. In other words,when the car is stopped at a floor during up car travel, the pointerI86, which is secured to frame 666, and represents the position of thecar, is at the line .iust below the central space. when the stop iswhich circuits made duringdown car travel, the pointer is at the linejust above the space.

Each mark on the scale represents one foot, those marks opposite thenumerals I, 2, 3, 4 and 5 representing 10, 20, 30, 40 and 50 feetrespectively. The scale and pointer are for setting the cams to operateat the proper points. Assume that it is desired to set the selector forfull advance for a 1000 feet per minute installation. The approximateslow down distance in feet for a 1000-feet per minute installation is 33feet. With the car at the floor level, the carriage is moved in onedirection to a point where pointer I86 is opposite the 33 foot mark onthe scale. The cam for switch I62 for the direction in which thecarriage has been moved is then set so that its leading edge engages theoperating roller for switch I62 so as to just crack open the switch. Thecam is then tightened on shaft 694 in this position. The carriage isthen moved in the opposite direction to the 33 foot mark where the othercam for switch I62 is set and tightened in a like manner. The otherselector switches are set to open at less distances from the floor, thesetting being accomplished in a similar manner by 'movingthe carriage toa point on the scale corresponding to the distance from the point atwhich it is desired to have the switch open. With the carriage moved therequired amount in one direction, the leading edge of the cam for that drection for the switch which is being set is movedlto position to justcrack open the switch where it is tightened on the shaft, and the camfor that switch for the other'direction of movement is'set in the sameway.

It is to be noted that the cams 692 and 693 for operating these switchesare formed in such way, as shown in Figures 3 and 4, that when the camis moved to a point whereit justv cracks open the switch which itoperates, the screws which clamp the cam to the shaft are readilyaccessible through the opening I81 in frame 666. 'The angular distancebetween the leading edges of the cams for operating switch I02, whichcause the final stopping operation, and the horizontal is due to .theworking clearance for the pawls I04 and and the amount of coast of thecar after the opening of the switch.

If the selector were adjusted for an installation in which the caroperated at a speed different from 1000 feet per minute, the cams onshaft 694 would be adjusted differently. For example,

for a 1200 feet per minute installation, the cams for operating switchI62 would be set to crack open the switchat about 43 scale. Thedistances at which the other switches to crack open theswitch with thecar about 6 feet from the floor, i. e., with the pointer on the 6 footmarks on the scale.

Regardless of the slow down distance, the carriage may be operated tofull advance position, i. e., 50 feet with the arrangement shown, bysetting stop collars H5 and IIS to permit this amount of movement. Thus,for the 400 feet per minute installation, the cams for operating switchI62 when fully advanced would have to be rotated back to where thepointer came opposite the 6 foot mark before permitting the opening 7feet from the floor, 1 i. e., with the pointer on the-43 foot marks onthe of the switch. If desired, thecollars may be set

